title: Roscovitine blocks leukocyte extravasation by inhibition of cyclin-dependent kinases 5 and 9.
abstract: OBJECTIVE
  Roscovitine, a cyclin-dependent kinase (CDK) inhibitor that induces tumour cell death, is under evaluation as an anti-cancer drug. By triggering leukocyte apoptosis, roscovitine can also enhance the resolution of inflammation. Beyond death-inducing properties, we tested whether roscovitine affects leukocyte-endothelial cell interaction, a vital step in the onset of inflammation.
  
  
  METHODS
  Leukocyte-endothelial cell interactions were evaluated in venules of mouse cremaster muscle, using intravital microscopy. In primary human endothelial cells, we studied the influence of roscovitine on adhesion molecules and on the nuclear factor-κB (NF-κB) pathway. A cellular kinome array, in vitro CDK profiling and RNAi methods were used to identify targets of roscovitine.
  
  
  RESULTS
  In vivo, roscovitine attenuated the tumour necrosis factor-α (TNF-α)-induced leukocyte adherence to and transmigration through, the endothelium. In vitro, roscovitine strongly inhibited TNF-α-evoked expression of endothelial adhesion molecules (E-selectin, intercellular cell adhesion molecule, vascular cell adhesion molecule). Roscovitine blocked NF-κB-dependent gene transcription, but not the NF-κB activation cascade [inhibitor of κB (IκB) kinase activity, IκB-α degradation, p65 translocation]. Using a cellular kinome array and an in vitro CDK panel, we found that roscovitine inhibited protein kinase A, ribosomal S6 kinase and CDKs 2, 5, 7 and 9. Experiments using kinase inhibitors and siRNA showed that the decreased endothelial activation was due solely to blockade of CDK5 and CDK9 by roscovitine.
  
  
  CONCLUSIONS
  Our study highlights a novel mode of action for roscovitine, preventing endothelial activation and leukocyte-endothelial cell interaction by inhibition of CDK5 and 9. This might expand its usage as a promising anti-inflammatory compound.
authors.affiliation: Department of Pharmacy, Pharmaceutical Biology, University of Munich, Munich, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Berberich
authors.forename: Bernd
authors.initials: B
authors.lastname: Uhl
authors.forename: Jos
authors.initials: J
authors.lastname: Joore
authors.forename: Ulrike K
authors.initials: UK
authors.lastname: Schmerwitz
authors.forename: Bettina A
authors.initials: BA
authors.lastname: Mayer
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Reichel
authors.forename: Fritz
authors.initials: F
authors.lastname: Krombach
authors.forename: Stefan
authors.initials: S
authors.lastname: Zahler
authors.forename: Angelika M
authors.initials: AM
authors.lastname: Vollmar
authors.forename: Robert
authors.initials: R
authors.lastname: Fürst
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D051360:Cyclin-Dependent Kinase 5 / Q000037:antagonists & inhibitors*; D042863:Cyclin-Dependent Kinase 9 / Q000037:antagonists & inhibitors*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000201:enzymology; D006098:Granulocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D006801:Humans; D007962:Leukocytes / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000098:blood supply; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011687:Purines / Q000494:pharmacology*; D000077546:Roscovitine
chemical_list: D047428:Protein Kinase Inhibitors; D011687:Purines; D000077546:Roscovitine; D051360:Cyclin-Dependent Kinase 5; D042863:Cyclin-Dependent Kinase 9